Gremlin motor/throttle/DX7s issues

[Jeff_RC]

First post - hoping that someone can show me what I'm missing.... ;>)

My transmitter throttle does not spin the motors. All transmitter functions seem to work however, and can be seen in Betaflight.

At this point, I have to believe the FC board, ESCs, Tx and Rx are working properly (see below). I wonder if there is something really obvious and stupid that I'm missing?


Deets:
Win7 Pro, 64bit. Connected thru USB hub
DX7s transmitter, what I think is the latest firmware 1.03
Spektrum serial receiver
Model setup Acro (plane), 11ms frame rate, DSMX

Receiver binds normally, all channels - sticks and aux1/2 - can be seen working in Betaflight.

Running BetaFlight 3.2.1. Connects normally (after the usual messing around with COM drivers), and the quad picture on screen reacts to both manual movements on 'setup' screen, and transmitter inputs on 'receiver' screen. I had to reverse my aileron setting on the DX7 to make the 'receiver'screen react properly.

Config screen:
Multishot, 8k gyro, 8k PID

Mode screen:
Arm is AUX1, transmitter moves control - loud beeps when armed. AUX2 is Angle/Horizon/nothing. Also beeps when switching.

Calibrated ESCs. They all work in manual 'motors' screen. Set min throttle after ARM to 1050. That is, in fact, lower than minimum stick value of about 1158.

BLHeliSuite32 (32.3.0.0) connects but does not recognize the ESCs. It does see 4 of them, but cannot identify, or read or write to the flash. I'm using the Chrome version instead.

BLHeli configurator in Chrome connects. Reads 'BTFL 3.2.1 Oct 15 2017...' firmware on FC board. Reads ESCs as 'P-H-10'.

I've tried ESC firmware versions 16.5, 16.63 DSHOT commands [Official], and 16.67RC [blheli-multishot]. They all behave the same. Currently running 16.5.

All ESC functions seem normal. Beeping during power on, programming changes, time out beeping after 5 minutes, etc.

Any thoughts are welcome - I'd like to add the props and fly this thing!

Thanks!

Jeff

 

[LitterBug]

Try dropping to 4k/4k or even 2k/2k. Maybe your CPU % is too high which is preventing it from arming.... Femto F3 is not the fastest, latest, greatest, uber spec FC.

Welcome to group therapy!

Cheers!
LitterBug

 

[French]

If you go to the receivers tab in betaflight, do the channels move with your stick movements? I assume they are. I also assume by “not spinning” you mean that it won’t arm. You can try this:

 

[PsyBorg]

I am pretty sure this is the standard issue Spectrum range is not wide enough to let the quad arm thing but there could be something else.Watch these two videos depending what gear you use more then likely the solution is in them. I turn all the unused junk off on my Femto and run 8k 8k and it only idles at 26% with defaults set it will idle at 36% and still be flyable IF you are running multishot like I am.

 

[Jeff_RC]

Thanks LitterBug!

Tried the 2k/2k and 4k/4k - no joy. ;>(

Given that it's working in all other aspects, I'm focused on the arming/ESC/throttle settings. I'm new to multirotor and not so old in RC for that matter, so I'm hoping it's some subtle ESC tribal knowledge I'm missing.

Recalibrated ESCs with LiPo out, manual mode full power, connect batt, proper ESC chirping, then down throttle and more proper chirping.

Failsafe modes??

J

 

[Jeff_RC]

French:

Thanks for the YouTube - I have a lot to learn - it's fun!

But. That does not seem to be it. CLI shows the arming disable flags for ARMSWITCH and CLI (1). When I toggle the arm (Aux1) it then only shows the CLI inhibit (2). It should be disabled during CLI if I learned anything today.... ;>)



J

 

[rrc1962]

To calibrate the ESC's, connect the board via USB but do not connect a battery. Go to Motors in Betaflight and move the master motor control to full throttle. Connect the battery and wait for the beeps, then go back to Betaflight and move the master control back to zero throttle and wait for the beeps.

Also make sure you changed all your travel ranges in the transmitter to 147. If you forget that, the throttle number Betaflight is seeing is above the minimum arm number and it will not arm.

 

[Jeff_RC]

PsyBorg:

Bingo! Thanks! First YouTube of standard checks for not arming.

min_check was too low to arm.

Now I need to find out how to re-adjust my Tx pwm outs - the range is somewhat narrow e.g. 1160 to 1850. THAT is another topic.

Off to attach props!!!

Everyone - thanks for your help!

J

 

[Jeff_RC]

Parting thoughts:

Did some research... Spektrum makes this a little goofy. Their nominal design PWM outputs are significantly narrower (80%) at 1102μs - 1898μs than the nominal 1000μs - 2000μs. Mine were narrower still at approx 1150μs - 1850μs.

It seems like this is fixed in the Spektrum TX product, and can't be adjusted as suggested by the YouTube example with a different vendor TX.

From the Horizon Hobby Spektrum Rx interfacing document:

9.1 “Servo Position” Ranges
A full range of “Servo Position” data ranges from 0 to 1024 or 0 to 2048 depending on the bind type.
These limits are equivalent to a ±150% travel setting in AirWare.
This full range translates to a range of 1194μs which when applied to a PWM servo signal equals
903μs to 2097μs
At ±100% travel, the data range is equivalent to a “Servo Position” data range of approximately 341 to
1707 which translated to PWM equals 1102μs to 1898 μs

 

[TazRC]

Did you actually try adjusting the travel?

DX7s: Travel adjust is in the Servo Setup menu. Click the roller from the main screen, roll to and then click on Servo Setup. Travel is the option that comes up first in the screen. Highlight, click on and roll to select the channel you wish to adjust. All should be close to 150% for ~1000-2000us.

 

[LitterBug]

AHhhhh.... Oh yeah. I've been down this path before. I use a TX profile with the servo travel set to 150%ish in both directions so all the channels send 1000-2000. Been so long since I did that, I had forgotten. When I build a new one, I just copy it to the new one and change the name and then bind.

Cheers!
LitterBug

 

[Jeff_RC]

Taz:

And THAT is why I'm on the internet looking for advice!

Thanks - no - I didn't know about that. And now I do! ;>)

Adjusted my TX, and now I'm looking for the phantom channel 8....

J

 

[LitterBug]

Guess it is also because I haven't run *flight in quite some time and am running dRonin firmware on mine. LOL

 

[French]

Jeff, glad that it seems you have it all working. These types of issues can be frustrating, but it’s rewarding when you get them figured out and learn a few things in the process.

 

[Jeff_RC]

Almost working... ;>)

The essential functions are worked out, and now the Gremlin arms, spins up - and seems somewhat out of control on the floor.

Holding it in my hand is more stable, but doesn't seem quite right. Now I need to go back and look at modes, make sure the motors are spinning the right way, correct props on correct spindles, etc. Double up on the sticky tape for isolation. Re-check and triple check. Normal pre-flight troubleshooting.

In the meantime, I ripped out one antenna and chopped an RX wire because I hadn't buttoned it down in my haste to try it. Dumb. Fixed the RX, and the RX receive seems ok for now on one antenna. Need a couple plane parts from Horizon anyway....

It's a learning curve - but that's one reason I wanted to try one!

 

[LitterBug]

Make sure you calibrate the Accelerometer in BF Configurator with the frame sitting level. My ACC (and I've heard others too) does not default to sitting level.

LB

 

[ElectriSean]

Not related to your problem, but you should set your min_check to around 1005 - 1010 (assuming you have your throttle range set properly). Leaving it higher essentially causes a deadband at the bottom of the stick.